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Introduction

Primary breast sarcomas are rare tumors. They originate from the mesenchymal tissue of the breast. The prevalence of primary breast sarcomas as reported at Mayo Clinic among breast cancers was found to be 0.0006% [1]

Among sarcomas of breast primary leiomyosarcoma iseven more rarely seen and less than 50 cases have been reported in the world literature. Most of the reported cases are between the age of fifty and eighty yearsand occurs usually in postmenopausal women. Most cases are low-grade and are cured by complete excision with wide margins.In the present study, we present a case of primary leiomyosarcoma of the breast which had axillary metastasis, and the first such case reported in literatureand we discuss optimal treatment options.

Case Presentation

A 40-year-old female patient was referred to our hospital because of a big ulcerated mass in the breast (Figure 1). She noticed a lump in her right breast 1 year ago and was on some ayurvedic medicine, but recently this lump had grown rapidly and led to the ulceration of the skin . Physical examination revealed 25/25 cm ulcerated lesion in thebreast. There was no retraction of the nipple but had palpable axillary nodes 2×2 cm. The contralateral breast was normal. Mammography detected a large mass (BIRADS 5).

Figure 1: Leimyosarcoma Breast

Core needle biopsy of the right breast revealed a spindle-cell neoplasm composed of tumor cells with blunt ended nuclei that were strongly positive for smooth muscle actin (SMA) and vimentin, and lacked expression of pan-cytokeratin, CD34, and S-100. This immunophenotype is most consistent with a diagnosis of breast sarcoma.

Microscopically, the tumor was composed of pleomorphic spindle cells showing frequent mitoses and necrosis. Tumor cells demonstrated diffuse immunohistochemical staining with smooth muscle actin (SMA). No staining was observed with desmin, S100, CD117. According to the histopathological and immunohistochemical analysis, the tumor was diagnosed as leiomyosarcoma.FNAC of the axillary nodes showed metastatic sarcoma. Modified radicalmastectomy was done as the tumor was large and had axillary metastasis.The patient is doing well and on regular follow up.

A follow-up thoracoabdominal computed tomography scan and bone scintigraphy performed 1 month after the operation were normal

Discussion

Primary leiomyosarcoma of the breast is an extremely rare malignant neoplasm of uncertain biological behavior. There are less than 50 well-documented cases reported in the English medical literature [1]. As this tumor is rare more patient data should be presented for the development of a proper treatment strategy.

The majority of these cases present as a well-circumscribed mass in the breast of postmenopausal women. The exact origin of the entity is not clear. The myofibroblasts in the nipple areola complex have been proposed as the origin for the neoplasm [2]. The mainstay treatment is wide margin local excision. Most reported cases have undergone mastectomy with a few exceptions being treated with lumpectomy. Axillary dissection is believed to be unnecessary as the primary leiomyosaroma of the breast does not spread through the lymphatic route, but as in our case it had metastasized to axillary nodes MRM was necessary and ours is first such case reported in literature.

To date, this type of tumor has been observed to affect middle-aged women and manifests as a mass in their breast over a long period of time. The average tumor size is 4.7 cm [3, 4]. The involvement of endocrine factors in this tumor appears to be unlikely as the two reported cases were in males [3]. This tumor tends to show local recurrence and distant metastasis has been observed in 25% of patients [5, 6]. Metastatic spreading usually occurs via the hematogenous route. Tumor size is believed to have no significant correlation with metastasis [5]. The studies published to date show that the tumor presents itself as a long-standing and slow-growing mass. The duration of symptoms varies between 2 weeks and 5 years, confirming those characteristics [5]. Local recurrence and distant metastases can arise even after 15-20 years [7]. Chen et al. [8] and Nielsen [9] lost their patients 16 and 20 years, respectively, after the operation due to hepatic and multiple metastases.

Leiomyosarcoma is characterized by spindle-shaped cells with pleomorphic, hyperchromatic and elongated nuclei; eosinophilic cytoplasm; large nucleoli; and significant mitoses. Definitive diagnosis is established through histological examination, in which positive staining is observed immunohistochemically with desmin, vimentin, and muscle-specific actin, whereas negative staining is seen with cytokeratin, myoglobin, and S-100 [10]. Leiomyosarcoma are generally strongly and uniformly positive for SMA and HHF35 (Figure 2).

Smooth muscle actin is more specific for smooth muscle than panactin HHF35. It is usually negative in skeletal muscle tumors in contrast to HHF35, which is frequently positive in these tumors. Desmin positivity varies with leiomyoma being usually at least focally positive, whereas LMS is positive in only 70% to 80% of cases, with less staining in the poorly differentiated examples.Calponin, a cytoskeleton-associated actin-binding protein, is frequently used as a myoepithelial marker but is also very useful in detecting smooth muscle differentiation in STTs. In addition to smooth muscle and myoepithelial cells, it is also expressed in myofibroblasts. It is consistently positive in leiomyoma, and it is positive in a high percentage of LMSs (90% in conventional LMS, 70% in pleomorphic LMS). To define a poorly differentiated spindle cell sarcoma as LMS, at least 2 of 3 muscle markers (using for example SMA/desmin/HHF35 or SMA/desmin/calponin) should be positive, and the H&E appearance should be supportive as well. Markers specific for skeletal muscle differentiation (myoglobin, myogenin) are consistently negative in LMS. Keratins and EMA are positive in 10% to 30% of LMSs [11]. Because leiomyosarcoma often invades peripheral tissues, such as the skin and fascia, curative surgery requires a wide resection. Because there has been no reported cases of lymph node metastasis in which dissemination occurred via the hematogenous route, axillary lymph node dissection is unnecessary if leiomyosarcoma diagnosis can be achieved before the operation [10], but our case is the first to show axillary nodal metastasis and thus importance of preoperative FNAC for any palpable axillary lymphadenopathy. Prognosis is determined primarily by the adequacy of surgical resection. Although, there is no definite consensus on the use of adjuvant chemotherapy or radiotherapy, most patients reported till date have done well without any chemotherapy or radiotherapy, at least in the initial few years (Table 1) . In the present case, there was axillary lymph node involvement. MRM was performed due to large ulcerated mass with invasion of the pectoralis major muscle by the tumor. The prognosis of leiomyosarcoma is better than that of other breast sarcomas [5]. The prognostic factors are not fully known because of the limited number of studies

They require long-term follow-up because local recurrence and distant metastasis can occur long after the operation. After surgical resection, late local recurrence and distant hematogenous metastasis to lungs and liver is, however, well-documented and bone metastasis has once been reported [12]. It has a better prognosis than other breast sarcomas. However, there is a need for further studies to determine the prognostic factors.

Conclusions

Leiomyosarcoma of the breast is a rare entity with patients typically being in the 5th−7th decade. Morphologically it can be suspected by the typical histological features of circumscription, high cellularity and being composed of fusiform spindle cells having blunt end nuclei. Confirmation by an immunohistochemical profile of smooth muscle actin, vimentin, and desmin positivity is helpful. The mainstay treatment is wide margin local excision. Axillary dissection is believed to be unnecessary as the primary leiomyosaroma of the breast does not spread through the lymphatic route.

Author’s Contribution

SN: Collection of data and involved in editing the article.

GP: Helped in finding the previous research material for the
article.

HQ: involved in collection of data and final editing of the
article.

BBP: Helped in analyzing the histopathological and
Immunohistochemistry.

Conflict of Interest

The authors declare that there are no conflict of interests.

Ethical Considerations

The written informed consent was obtained from the patient for publication of this case report. The copy of the consent is available with the authors.